mirror of https://github.com/pyodide/pyodide.git
28 lines
891 B
Python
28 lines
891 B
Python
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#setup: N=50
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#run: julia(1., 1., N, 1.5, 10., 1e4)
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#pythran export julia(float, float, int, float, float, float)
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import numpy as np
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from time import time
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def kernel(zr, zi, cr, ci, lim, cutoff):
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''' Computes the number of iterations `n` such that
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|z_n| > `lim`, where `z_n = z_{n-1}**2 + c`.
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'''
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count = 0
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while ((zr*zr + zi*zi) < (lim*lim)) and count < cutoff:
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zr, zi = zr * zr - zi * zi + cr, 2 * zr * zi + ci
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count += 1
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return count
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def julia(cr, ci, N, bound=1.5, lim=1000., cutoff=1e6):
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''' Pure Python calculation of the Julia set for a given `c`. No NumPy
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array operations are used.
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'''
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julia = np.empty((N, N), np.uint32)
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grid_x = np.linspace(-bound, bound, N)
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for i, x in enumerate(grid_x):
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for j, y in enumerate(grid_x):
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julia[i,j] = kernel(x, y, cr, ci, lim, cutoff)
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return julia
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